A GAS-CHROMATOGRAPHIC HEADSPACE METHOD FOR THE DETERMINATION OF ACETONE IN BOVINE-MILK, BLOOD AND URINE

An automated headspace gas-chromatographic method has been developed for the determination of acetone in the milk, blood and urine of dairy cows. Five ml samples were saturated with 2 g of sodium chloride and equilibrated for 30 min at 90-degrees-C in a Hewlett-Packard HP 19395A automatic headspace sampler. The headspace volatiles were transferred without splitting to a 25 m x 0,3 mm x 0,4-mu-m Carbowax column in a Shimadzu GC 9A gas chromatograph, operating isothermally at 50-degrees-C. The coefficients of variation for the determination of acetone were 1,5-4,4 % for urine, 10,0-24,9 % for milk and 2,0-19,6 % for blood. The detection limits were 0,0055 mg/100 ml for milk, 0,0072 mg/100 ml for blood and 0,0080 mg/100 ml for urine. The analysis time of 5 min per sample provided an adequate rate of throughput for routine monitoring.